GMAC reported that 85% of drivers incorrectly answered a question asking them what they are supposed to do when approaching a yellow light. (The correct answer is slow down and proceed through the light only if it is safe to do so. But I’m sure you already knew that.) To verify this surprising result, 330 drivers in a random sample were asked the same question.

From this sample, 274 answered incorrectly. Using a 90% confidence interval, are the results reported by GMAC validated?

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